What Size Wire Should be Used for the 12V Power Supply and Ground Pins on a 7-Way Trailer Connector

Question:

What gauge wire for the charge line? Ive seen 10 gauge as minimum. Also, what gauge ground wire? Where do I connect charge wire? to the battery directly, or to the battery terminal on the alternator? Plan to use a 40 amp self resetting fuse in the line. Thank you for your help.

asked by: jim h

Expert Reply:

When we install a 7-Way, we run the 12V power wire directly to the positive terminal on the battery with a 20, 30, or 40 amp auto-reset circuit breaker, like part # 9506P, 38630, or 9510. If you are using a 40 amp breaker you will definitely want to use 10 gauge wire.

We also recommend using 10 gauge for ground wires on 7-Way connectors. That is how we wire them in house and most of the 7-Way connectors are molded for 10 gauge wire in the ground pin.

expert reply by: Patrick B